21-Day Bikini-Body Challenge

Day 1: Get Adequate Amounts of Sleep

Day 1: Get Adequate Amounts of Sleep

Though it may be tempting to stay up watching the contents of your DVR, studies suggest that getting seven to eight hours of shut-eye a night is necessary to ward off weight gain. Separate research done by the University of Chicago and University of Pennsylvania, for example, revealed that sleep-restricted subjects gained more weight over time than those who were well rested. Culprits behind sleep-deprived weight gain are believed to be leptin and ghrelin, two hormones that affect how full you feel. When you’re short on sleep, levels of leptin (an appetite suppressant) fall and levels of ghrelin (an appetite stimulant) rise—so you feel hungrier than you would otherwise.

Day 2: Detox Responsibly

Day 2: Detox Responsibly

Don’t let the bad rap that certain cleanses have received turn you off to the nutrient-rich benefits of juicing. “Doing a three-day juice fast through a program like Blueprint Cleanse or Organic Avenue is a safe and healthy way to detox,” says Oz Garcia, PhD, nutrition specialist to Heidi Klum and Hilary Swank. For maximum comfort and effects, Eric Helms, cofounder of the new Cooler Cleanse (Salma Hayek is his business partner), stresses the importance of easing your body in and out of the practice. One to three days before and after, consume nutritious, easily digestible foods and avoid anything processed, caffeinated, alcoholic, sugary, or artificially flavored. Red meat, dairy products, and nonorganic peanut butter are also on Helms’ do-not-eat list.